(1) Field of the Invention
The present invention relates to novel water and oil repellants which can impart soft feeling to textile products and the like and can show excellent water and oil repellency even after washing or dry cleaning.
(2) Description of the Related Art
Water and oil repellants comprising a comopolymer of a (meth)acrylate, which contains a perfluoroalkyl group, or a copolymer of the (meth)acrylate and another polymerizable compound such as an alkyl (meth)acrylate, vinyl chloride, butadiene, maleic anhydride, styrene or methyl vinyl ketone have been known and widely employed for many years. The term "(meth)acrylate" as used herein should be interpreted as including both an acrylate and a methacrylate.
Treatment of a textile product with a water and oil repellant which comprises a polymer composed principally of such a perfluoroalkyl-containing (meth)acrylate however results in hard feeling. This is certainly a serious drawback, especially, when applied to dresses and the like.
In addition, a water and oil repellant which comprises a polymer composed principally of such a perfluoroalkyl-containing (meth)acrylate is accompanied by another drawback that textile products treated with the repellant show excellent water and oil repellency in the beginning but the water and oil repellency is considerably reduced after washing or dry cleaning.
With a view toward improving the durability against washing and dry cleaning, it has also been proposed to copolymerize one or more of various crosslinking monomers or to mix a melamine compound, a blocked isocyanate compound or the like with a treatment solution and then to apply water and oil repellant treatment. The methods whose effectiveness has been recognized all result in very hard feeling, so that they can be used only for extremely limited applications. Therefore, these methods have poor utility.
To soften the feeling, a silicone-type softener may be used in some instances along with a water and oil repellant, which comprises a perfluoroalkyl-containing polymer, so as to improve the feeling. However, it has generally been known that where softening effects are observed from the combined use of a silicone-type softener, the silicone-type softener gives deleterious effects to the water and oil repellency of a water and oil repellant which comprises a perfluoroalkyl-containing polymer.